How unpredictable access to food increases the body fat of small passerines: A mechanistic approach
How unpredictable access to food increases the body fat of small passerines: A mechanistic approach
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DOI：
10.1016/j.beproc.2017.08.013
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发表时间：
2017-11-01
影响因子：
1.3
通讯作者：
Guentuerkuen, Onur
中科院分区：
文献类型：
--
作者：
Anselme, Patrick;Otto, Tobias;Guentuerkuen, Onur
不可预测的奖励增加了自动成形（巴甫洛夫条件反射程序）中反应的活力，并且在涉及固定与可变延迟时间表的自由选择任务中优于可预测的奖励。这些行为特性在现场条件下可能具有的意义目前尚不清楚。然而，值得注意的是，当暴露在不可预测的食物中时，小雀形目鸟类-如知更鸟，山雀和椋鸟-比食物丰富时更胖。在功能方面，增肥被视为一种进化策略，在食物短缺时对抗饥饿的风险。但是这种功能观点并不能解释小型雀形目在食物不确定性下变得更胖的因果机制。在这里，有人建议，这些因果关系的机制之一是参与行为的激励和偏好的食物不确定性在实验室中。基于食物不确定性下动机变化的心理学理论，我们开发了一个综合计算模型来验证这一想法。我们发现，由于功能（适应）的原因，奖励的不可预测性的兴奋性可以支持野生鸟类觅食的倾向更长和/或更密集的不可预测的环境中，其后果是，他们可以把更多的脂肪储备。
Unpredictable rewards increase the vigor of responses in autoshaping (a Pavlovian conditioning procedure) and are preferred to predictable rewards in free-choice tasks involving fixed- versus variable-delay schedules. The significance those behavioral properties may have in field conditions is currently unknown. However, it is noticeable that when exposed to unpredictable food, small passerines - such as robins, titmice, and starlings get fatter than when food is abundant. In functional terms, fattening is viewed as an evolutionary strategy acting against the risk of starvation when food is in short supply. But this functional view does not explain the causal mechanisms by which small passerines come to be fatter under food uncertainty. Here, it is suggested that one of these causal mechanisms is that involved in behavioral invigoration and preference for food uncertainty in the laboratory. Based on a psychological theory of motivational changes under food uncertainty, we developed an integrative computational model to test this idea. We show that, for functional (adaptive) reasons, the excitatory property of reward unpredictability can underlie the propensity of wild birds to forage longer and/or more intensively in an unpredictable environment, with the consequence that they can put on more fat reserves.